


Pheebs Assistance

by Moonstone_Plus



Category: The Thundermans
Genre: Brother-Sister Relationships, Brother/Sister Incest, Cunnilingus, F/M, Finger Sucking, Fingerfucking, Growing Up, Hot, Hot Sex, Incest, Oral Sex, Puberty, Pubes, Sex, Sibling Incest, Underage Sex, Vaginal Fingering, Vaginal Sex
Language: English
Status: In-Progress
Published: 2021-02-09
Updated: 2021-02-09
Packaged: 2021-03-14 18:48:02
Rating: Explicit
Warnings: Underage
Chapters: 1
Words: 3,049
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/29300649
Author URL: https://archiveofourown.org/users/Moonstone_Plus/pseuds/Moonstone_Plus
Summary: As he grows up, Billy meets a new issue in pre-teen life and comes to Phoebe to sort things out - only in a way sisters wouldn't usually do.
Relationships: Billy Thunderman/Phoebe Thunderman
Comments: 1
Kudos: 6





	Pheebs Assistance

Billy Thunderman had a issue and the two people that could actually help him, were out.

It was one of the few times he hated having superheros for family members, when he needed to discuss guy stuff, he had to wait until his father or brother was home. Once they were home, they didn’t always want to talk to him anyway since they thought that he was a idiot at times and some of his questions were a little too ridiculous. Like the time he had gotten his first erection and thought that he had broken his cock while playing with Nora. Max didn’t stop laughing for hours at him when he explained that he had been playing with Nora and his cock had broke.

Luckily his father had been more helpful, when he himself stopped laughing.

Today, however he wasn’t able to wait. He was craving a answer now and there was only one person in the house that would be able to help him. Even if he didn’t really want to talk about his private parts with her, he had no choice if he wanted to get his answer before Max or his father returned home and simply laughed at him. 

He had to ask his older sister.

"PHOEBE!"

"What!" Phoebe groaned. Knowing that she going to be interrupted by her slightly idiotic little brother, with the boy finding him in her room "What's wrong this time, Billy?"

"I-I uh need your help…" Billy replied, nervously.

"What do you need my help with?" Phoebe asked curiously, with Billy nervously sighing before going on with his plan.

"I-I got hair…" Billy admitted softly causing his older sister to roll her eyes a little.

"I know Billy, EVERYONE has hair…" Phoebe replied softly. The girl placed her hands on her head like she was talking to a child. "Billy… everyone has hair on their heads…"

"I don't mean HEAD Hair… I have hair, you know…" Billy continued, with the boy blushing a little from the conversation. Wondering why he didn’t just wait until Max was home for this conversation. "D-down there!"

"Um, down where Billy?" Phoebe asked curiously, with the older girl deciding to try a different place than where she was beginning to think "Do you mean your legs?"

"What! NO! I mean… my special area!" Billy exclaimed, blushing heavily.

"Oh! Oh god… you mean your… um private area, don't you?" Phoebe replied, with the girl blushing a little from the fact her little brother had come to talk to her about growing pubic hair. Why couldn't he go to their dad or even Max about this, with a groan and a hope that Billy wouldn't end up showing her said hair, she continued "It's uh normal Billy! I think that uh Mom and Dad have some books on it downstairs… or um, you could just wait until Dad gets home…"

"But!" Billy protested. "B-but! It doesn't look normal! It looks weird and WRONG!"

"Billy! Trust me, it's Normal!" Phoebe responded with a loud sigh, knowing that she couldn't scream out in frustration like she wanted.

"But LOOK!" Billy exclaimed loudly as he fingered the waistband of his shorts and boxer briefs before pulling them down to reveal himself to his older sister.

"BILLY! What the…" Phoebe almost screamed, from the shock of seeing her little brother's crotch and cock. The older girl couldn't stop herself from almost staring at her little brother's cock, which was beginning to harden from what she believed was due to her attention. Phoebe continued to stare at Billy's cock for a few moments before finally coming down from the shock and exclaiming: "Billy! Cover Up!"

"Huh, Why?" Billy asked, confused before looking down and finally noticing that he was hard. "Oh… um… sorry, it just does that without warning…"

"You don't um… need to be sorry Billy, it's uh… I mean there's nothing wrong with it… its very normal for b-boys your age to get erections…" Phoebe managed to get out despite feeling a little awkward about the entire thing. The girl was once again wishing that her parents or even Max would be here to deal with this instead of her.

"So it's normal? And nothing is wrong with it?" Billy asked.

"Yes Billy, it's normal and there's absolutely nothing wrong with it…" Phoebe responded, with the girl wondering how she would be able to un-see her little brother's cock. If she had to have seen any of her brother's cock, she would have at least preferred that it was her twin brother's Max's. She had been hearing some rumours at school that Allison had been bragging about Max's cock and how good of a lover he was.

"B-but how are you so certain? Can you make sure?" Billy asked with the boy pretending to be nervous despite this still being part of his plan.

"Uh! How did you want me to make sure it's fine Billy?" Phoebe asked with a very nervous gulp, hoping that her little brother didn't want her to touch his cock.

"Um… I don't know, could you um… touch it and make sure that everything is okay like the doctor does?" Billy offered.

"What BILLY! No! I'm not touching your cock!" Phoebe exclaimed, shocked that Billy would even suggest something like that.

"Phoebe! Please!" Billy begged.

"Ugh! Fine… but don't tell anyone!" Phoebe said with a loud sigh, as she reached down and wrapped her hand around her little brother's cock.

"So… is it fine?" Billy asked curiously, the boy holding back a moan from the fact his sister had her hand around his cock.

"It's fine Billy…" Phoebe answered awkwardly, with the girl quickly letting go of her little brother's erection.

"B-But How did you know! You didn't even look at it up close like the doctor does! How do you know from just a quick grab?" Billy protested with the boy wondering if he could milk this further and get more than just a grab.

"Ugh, trust me, Billy, it's fine!" Phoebe exclaimed before sighing loudly when she saw that Billy wasn't going to drop this.

As she found herself in front of her little brother's cock, Phoebe had to admit that he was a good size for his age and if he wasn't her brother then he would have considered doing something with him. While her family didn't know, she had fooled around with Link a number of times and after meeting the boy, she had even convinced Link to fool around with his brother in the terms of a threesome with her. She wasn't going to lie and say that her brother's hadn't caught her attention since Billy was a cute boy while her twin brother was a good looking dude even if he was trying to be a supervillain.

"It looks pretty good Billy…" Phoebe said as she attempted to make it look like she was giving her little brother's cock a good once over with the girl reaching out and wrapping his hand around his cock again.

"Oh god…" Billy moaned softly, as his sister started to move his hand back and forth.

"Yep, it's definitely normal…" Phoebe whispered as she continued to stroke her little brother's cock, with the girl not really knowing why she was doing this.

"Phoebe…" Billy moaned from the feeling. "P-Pheebs, w-what are you doing?"

"Well, since you have been a good boy as I gave you your check out… I'm going to give you something that only big boys with hair can get…" Phoebe responded, with Billy’s eyes widen from the shock at the lustful tone of normally fairly plain girl.

"D-does Max get them?" Billy decided to ask, with the boy attempting to play stupid.

"Well, he might get them from Allison… but he's not good enough to get them from anyone else..." Phoebe replied.

"Oh…" Billy replied, not knowing how to answer.

"Are you ready Billy?" Phoebe asked softly, with Billy nodding as she leaned in and took the mushroom head of his cock into his mouth. Billy's eyes widened from the shock with the boy releasing a loud moan from the feeling of someone sucking on his cock for the first time in his life. 

"Oh god, Phoebe…" Billy moaned, which caused the older girl to smile from the reaction since they reminded her of the little moans that Harris had released when she sucked his slightly smaller than Billy's cock.

Phoebe shocked her brother's by reaching around in order to grab onto Billy's ass, with the brunette using it to stabilize herself as she started to bob on his cock. Billy released another moan when he felt Phoebe giving his ass a firm squeeze. Billy had never expected a blowjob and was releasing moans like crazy from the pleasure. Phoebe continued to bob back and forth on her little brother's cock for a few moments before deciding to try something else.

"W-why did you stop?" Billy protested, with Phoebe not responding as his sister turned him around. Phoebe leaned in and ran her tongue up the length of her little brother's ass crack. When he felt her tongue against his hole, Billy yelped: "Phoebe!"

"Relax Billy! It will feel good…" Phoebe said while hoping that Billy would love it as much as Link did.

"B-but it feels weird!" Billy complained with the older girl not responding in any way but continuing to rim her little brother.

"Billy! Relax…" Phoebe ordered with a sigh when she heard the boy yelp.

"Fine…" Billy groaned as he attempted to relax his body a little to allow his sister to tongue fuck his ass.

‘Fuck… who knew that Billy’s moans were that's hot…’ Phoebe thought, when noticing that the younger boy was releasing more moans then whines now.

"Pheebs!" Billy whined, much to the amusement of the girl when she pulled back.

"While big boy's get some fun, they also have to return the favor Billy" Phoebe replied to him, with the girl still feeling a little weird by the fact she was actually being sexual with her adorable little brother.

"But you don't have a cock!" Billy exclaimed.

"Yes Billy, I don't have a cock…" Phoebe said with a sigh, due to how innocent her brother was "... but there are ways that a boy can make a girl feel good."

"Oh…"

"Do you want to learn?" Phoebe asked with Billy nodding curiously "Okay, first you have to remove your shirt…"

"Um… okay…" Billy said as he quickly removed his shirt, with Phoebe taking in the sight that her twin brother had already enjoyed "Now what?"

"Now you help me get undressed so I can join you naked…" Phoebe responded with Billy feeling his cock twitch from the thought of seeing Phoebe naked.

"Okay…" Billy replied nervously as he moved over to his sister, with the girl grinning at the sight of his erect cock swinging between his legs.

In order to help Billy feel like more of a man, Phoebe allowed her little brother to grab her shirt before she bent over to allow him to remove it. Billy blushed a little when he took in the sight of her bra covered breast. Phoebe grinned and motioned for the younger boy to remove her bra; with Phoebe noticing that Billy was definitely enjoying the view. Billy blushed as he reached around Phoebe and attempted to remove her bra, failing a few times before getting it. 

"What do you think of them, Billy?" Phoebe asked with a grin when she saw her little brother almost drooling with the younger boy only able to nod as he continued to stare at his sister's breasts.

"Do you want to touch them Billy?"

"Y-yeah!" Billy exclaimed with a grin, with Phoebe grabbing her little brother's hand and leading it to one of her breasts with Billy moaning a little from the feeling. Phoebe grinned a little when her little brother gave it a gentle squeeze before rubbing his finger against her nipple.

"Having fun?" Phoebe asked curiously as she watched her brother change his focus to the other tit.

"Y-yeah…" Billy blushed.

"Well, remember that you need to remove the rest of my clothes…

"Oh!" Billy replied with his blush getting worse, as he realised that he had forgotten what he was meant to do while playing with her tits. The twin's rolled their eyes a little when Billy quickly let go of Phoebe's tits like they were now diseased, before reaching down in order to undo her skinny jeans. The younger boy gulped a little when they dropped to the floor to leave his sister in only her panties. As Billy fingered Phoebe's panties, with the younger boy revealing that she was shaven. 

With his sister now completely naked, Billy asked: "So now, what do we do?"

"Well one thing that a big boy does for a girl is to her eat her out, do you want to try that Billy?" Phoebe asked, with Billy and Max watching as she walked over to her bed and laid down. The youngest of the Thunderman Brothers found their cock throbbing when Phoebe spread her leg and gave them a clear view of her shaven pussy.

"Eating out? Is that like eating a hamburger?" Billy asked curiously.

"No, it means that you use your tongue to lick and tease my pussy like I was doing to your ass…" Phoebe replied, a little amused at what Billy thought.

"Do you want me to stick my tongue in there?" Billy asked as he remembered what she did to him.

"If you want to Billy…" Phoebe replied, with the girl using her finger to rub her clit gently in order to get it ready for her little brother.

"Um, okay…" Billy replied nervously as he climbed between his sister's legs, with the boy wondering if her shaven pussy would taste differently to a hairy one.

Phoebe watched on slightly as Billy leaned down and ran his tongue up the length of her clit before finding herself closing her eyes and enjoying the feeling of Billy beginning to eat her out, with the younger boy using an eagerness that her boyfriend could never archive. Billy occasionally looked up to see if he was making his sister feel good before returning to pleasuring his sister. Phoebe found herself shocked when she felt her little brother's tongue pushing into her pussy and knew that she had to stop him before she squirted over his face.

"Billy! Stop!" Phoebe exclaimed after a while.

"B-but…" Billy protested but followed the order and pulled back.

"Okay Billy, it's time for something else…" Phoebe grinned, "Instead of licking it, I want you to use your finger…"

"You want me to put my finger in your pussy?"

"Yes, and it doesn't matter which finger…" Phoebe said, with the girl knowing that she had to add that to stop him from getting more confused.

"Um okay…" Billy replied nervously as he got into a comfortable position, before slipping one of his fingers into his older sister's pussy.

"Mm…" Phoebe moaned from the feeling of Billy's little finger sliding into her.

As he moved his fingers back and forth, Billy listened to the moans of his sister which seemed to get louder when he changed up the pace. Phoebe was impressed at the speed of Billy picking up fingering and continued to release moans as a way to encourage him. However, as the pleasure got too much for her, she forgot to warn her little brother of her orgasm until she was squirting her juices. Billy continued for a few moments before pulling his now soaked finger out of his sister's pussy.

"EW!" Billy groaned from the feeling of Phoebe's juices on his fingers.

"Just suck it off of your finger Billy, it tastes goods…" Phoebe said.

Billy shrugged a little and sucked on the covered finger, with the boy agreeing that it wasn't too bad. Phoebe blushed a little when Billy sucked the rest of her juices off of his fingers, with the girl watching as his tongue snaked around every finger in an attempt to get very drop of her juices.

“It really does…” Billy muttered, once he had finished enjoying the pussy juices of his older sister. 

While wondering what the juices of his best friend and young sister Nora would taste like in comparison to this. He was a little confused however when that curiosity grew to wonder what his own and Max’s cum juice would taste like. The last time he had tasted it was when it was still fairly watery and just beginning to come out of him and it was a bit salty but it had changed since then.

“So what else can we do together?” Billy pushed.

Despite the urge to just give in and continue to fool around with her little brother and see what his mouth would be actually fucking her rather then just finger fucking it or eating out it, but her conscious was playing up. She shouldn’t be wanting to feel her little brother’s cock in her as much as she was wanting to. This was as bad as the time she fingered herself to her best orgasm in her short life to the thought of Max’s cock fucking her deep with his lengthy cock. With the thought process changing locations from Max fucking her missionary style on her bed to Max forcing her to bend over in the shower and pounding her pussy like she was his sexual bitch until he exploded deep inside of her. It was the image of Max shooting her load deep inside of her pussy that finally broke the girl’s fantasy and had the girl’s juices flooding out of her.

She hadn’t looked at Max the same way for a long time.

Which wasn’t helped by the fact it was summer and Max had taken to walking around shirtless with the waistband of his underwear peeking out from under his shorts. She was just glad that she hadn’t caught him jerking off. That would have her craving her twin brother more than she already was.

“I don’t know… we shouldn’t be doing this Bill… we should stop” Phoebe started.

Pouting heavy, Billy whined. “W-Whyyy…”


End file.
